Is Breast Cancer Overdiagnosed in Older Women?

This week, the Annals of Internal Medicine published a study called “Estimating Breast Cancer Overdiagnosis After Screening Mammography Among Older Women in the United States.” The study suggests that about 31% of breast cancers in women age 70 to 74 are overdiagnosed. The authors interpret the results to mean that overdiagnosis may be common in older women and ask this question: Are the harms of overdiagnosis — unnecessary tests and treatments, anxiety, lower quality of life — balanced by the benefits of early detection of breast cancer?

The researchers defined overdiagnosis as the detection of a cancer, often through screening, that would not have caused symptoms in a person’s lifetime.

It’s extremely important to know that this was a retrospective study, meaning the researchers were looking at information on breast cancer screening and diagnosis that had already been collected. They  had information on the characteristics of the cancers and knew the outcomes. They knew if the cancers caused symptoms and affected a woman’s health and life. It's easy to make recommendations in hindsight when you have full information, but for someone trying to make the best decision today for herself, without the benefit of full information, it's a different story. In fact, that's what most people are up against. That's reality.

If you have a mammogram that shows a suspicious area, it’s impossible to tell from just that one mammogram if the cancer will affect your life and health or not.

Our tools for detecting breast cancer are improving quickly, but we don’t have a crystal ball to tell the future and know the difference between a lethal cancer and one that’s unlikely to affect you during your lifetime. Guessing at the extent and nature of the cancer can be like a game of Russian roulette. 

Of course, no one wants to have treatment for a cancer that would never cause problems. But since we don’t know how a cancer will behave in the future, why should a certain age stop someone from being screened and treated for breast cancer — and getting the benefit of early detection?

Women age 70 and older should talk to their doctor about the risks and benefits of breast cancer screening, taking into account their personal preferences, health, and their values around risk.

Many women age 70 and older have already experienced decades of ageism and invisibility. They deserve to decide for themselves if they want to continue with routine screening mammograms. They also deserve the right to exercise their own autonomy after thoughtfully evaluating the pros and cons of treatment, if they’re diagnosed.

So the bottom line is: If you would want the benefit of early detection and you are prepared to be treated for breast cancer, if one is found, then you should continue having regular mammograms, no matter how old you are.